J. G. Panduro Vazquez
A5102742880- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Advanced Data Storage Technologies
- Superconducting Materials and Applications
- Muon and positron interactions and applications
- Nuclear physics research studies
- Particle accelerators and beam dynamics
- Big Data Technologies and Applications
- Nuclear reactor physics and engineering
- Stochastic processes and statistical mechanics
- Nuclear Physics and Applications
- Structural Analysis of Composite Materials
Royal Holloway University of London
2016-2025
Rutherford Appleton Laboratory
2024-2025
Institute of Particle Physics
2024
The University of Adelaide
2014-2023
National Institute for Subatomic Physics
2023
University of Amsterdam
2023
Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Udine
2023
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2023
University of California, Santa Cruz
2014-2022
Chinese University of Hong Kong
2020
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce light mediator, so-called photon (A′), connecting sector to standard model. We present search for reaction e+e−→γA′, A′→e+e−, μ+μ− using 514 fb−1 data collected with BABAR detector. observe no statistically significant deviations from model predictions, and we set 90% confidence level upper limits on mixing strength between at 10−4−10−3...
We search for single-photon events in 53 fb−1 of e+e− collision data collected with the BABAR detector at PEP-II B-Factory. look a single high-energy photon and large missing momentum energy, consistent production spin-1 particle A′ through process e+e−→γA′; A′→invisible. Such particles, referred to as "dark photons," are motivated by theories applying U(1) gauge symmetry dark matter. find no evidence such processes set 90% confidence level upper limits on coupling strength mass range mA′≤8...
Many models of physics beyond the Standard Model predict existence new Abelian forces with gauge bosons mediating interactions between "dark sectors" and Model. We report a search for dark boson Z' coupling only to second third generations leptons in reaction e+e- -> mu+mu- Z', using 514 fb-1 data collected by BABAR experiment. No significant signal is observed masses range 0.212 - 10 GeV. Limits on parameter g' as low 7x10^-4 are derived, leading improvements bounds compared those...
We search for the rare flavor-changing neutral current process $B^{+}\rightarrow K^{+}τ^{+}τ^{-}$ using data from BABAR experiment. The sample, collected at center-of-mass energy of $Υ{(4S)}$ resonance, corresponds to a total integrated luminosity 424 fb$^{-1}$ and 471 million $B\overline{B}$ pairs. reconstruct one $B$ meson, produced in $Υ{(4S)}\rightarrow B^{+} B^{-}$ decay, many hadronic decay modes activity compatible with K^{+} τ^{+}τ^{-}$ rest event. Each $τ$ lepton is required...
We study the lepton forward-backward asymmetry ${\mathcal{A}}_{FB}$ and longitudinal ${K}^{*}$ polarization ${F}_{L}$, as well an observable ${P}_{2}$ derived from them, in rare decays $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, where ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ is either ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, using full sample of 471 million...
We study the processes $e^+ e^-\to K_S^0 K_L^0 \gamma$, $K_S^0 \pi^+\pi^-\gamma$, and K^+K^-\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ data collected with BaBar detector at SLAC. observe $\phi(1020)$ resonance in K_L^0$ final state measure product its electronic width branching fraction about 3% uncertainty. present measurement $ energy range...
The ATLAS Phase-I upgrade (2019) requires a Trigger and Data Acquisition (TDAQ) system able to trigger record data from up three times the nominal LHC instantaneous luminosity. Front-End LInk eXchange (FELIX) provides an infrastructure achieve this in scalable, detector agnostic easily upgradeable way. It is PC-based gateway, interfacing custom radiation tolerant optical links front-end electronics, via PCIe Gen3 cards, commodity switched Ethernet or InfiniBand network. FELIX enables...
We study the rare B meson decays B±,0→J/ψK+K−K±,0, B±,0→J/ψϕK±,0, and search for B0→J/ψϕ, using 469×106 B¯B events collected at Υ(4S) resonance with BABAR detector PEP-II e+e− asymmetric energy collider. present new measurements of branching fractions a J/ψϕ mass distribution in charmonium-like states. In addition, we decay B0→J/ψϕ find no evidence signal.1 MoreReceived 31 July 2014DOI:https://doi.org/10.1103/PhysRevD.91.012003© 2015 American Physical Society
An angular analysis of the decay ${\overline{B} \rightarrow D^\ast \ell^- \overline{\nu}_\ell}$, $\ell\in\{e,\mu\}$, is reported using full $e^+e^-$ collision data set collected by \babar experiment at $\Upsilon(4S)$ resonance. One $B$ meson from ${\Upsilon(4S)\to B\overline{B}}$ fully reconstructed in a hadronic mode, which constrains kinematics and provides determination neutrino momentum vector. The semileptonic described di-lepton mass squared, $q^2$, three angles. first unbinned fit to...
We present a search for neutral, long-lived particle L that is produced in e+ e- collisions and decays at significant distance from the interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an data sample with luminosity 489.1 fb(-1) collected by BABAR detector ϒ(4S), ϒ(3S), ϒ(2S) resonances just below ϒ(4S). Fitting two-track mass distribution signal peak, we do not observe signal, set 90% confidence level upper limits on product production...
We study the process $e^+e^- \to \pi^+\pi^-\eta \gamma$, where photon is radiated from initial state. About 8000 fully reconstructed events of this are selected BaBar data sample with an integrated luminosity 469~fb$^{-1}$. Using $\pi^+\pi^-\eta$ invariant mass spectrum we measure \pi^+\pi^-\eta$ cross section in $e^+e^-$ center-of-mass energy range 1.15 to 3.5 GeV. The well described by Vector-Meson Dominance model four $\rho$-like states. observe $49\pm9$ $J/\psi$ decay $\pi^+\pi^-\eta$,...
Based on a sample of 500 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events recorded by the BABAR detector at c.m. energies close to 10.6 GeV, we report study decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$. We measure ratio branching fractions,...
We study the processes $\gamma \gamma \to \eta_c \eta' K^+ K^-$, $\eta' \pi^+ \pi^-$, and $\eta \pi^-$ using a data sample of 519 $fb^{-1}$ recorded with BaBar detector operating at SLAC PEP-II asymmetric-energy $e^+e^-$ collider center-of-mass energies near $\Upsilon(nS)$ ($n = 2,3,4$) resonances. This is first observation decay $\eta_c K^-$ we measure branching fraction $\Gamma(\eta_c K^-)/(\Gamma(\eta_c \pi^-)=0.644\pm 0.039_{\rm stat}\pm 0.032_{\rm sys}$. Significant interference...
A dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented using the full BABAR data sample. For first time results are at next-to- next-to-next-to-leading order, with one two photons, respectively, for from initial final states. Comparison predictions phokhara afkqed Monte Carlo generators performed, revealing discrepancies one-photon rates angular distributions former. This disagreement has a negligible effect on e+e−→π+π−(γ)...
We present Dalitz plot analyses for the decays of $B$ mesons to ${D}^{\ensuremath{-}}{D}^{0}{K}^{+}$ and ${\overline{D}}^{0}{D}^{0}{K}^{+}$. report observation ${D}_{s1}^{*}(2700{)}^{+}$ resonance in these two channels obtain measurements mass $M({D}_{s1}^{*}(2700{)}^{+})={2699}_{\ensuremath{-}7}^{+14}\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ width $\mathrm{\ensuremath{\Gamma}}({D}_{s1}^{*}(2700{)}^{+})={127}_{\ensuremath{-}19}^{+24}\text{ }\mathrm{MeV}$, including statistical systematic...
We study the processes γγ→K+K−η and γγ→K+K−π0 using a data sample of 519 fb−1 recorded with BABAR detector operating at SLAC PEP-II asymmetric-energy e+e− collider center-of-mass energies near Υ(nS) (n=2,3,4) resonances. observe ηc→K+K−π0 ηc→K+K−η decays, measure their relative branching fraction, perform Dalitz plot analysis for each decay. K∗0(1430)→Kη decay its fraction to Kπ mode be R(K∗0(1430))=B(K∗0(1430)→Kη)B(K∗0(1430)→Kπ)=0.092±0.025+0.010−0.025. The results correspond first...
The process $e^+e^- \to \pi^+\pi^-2\pi^0\gamma$ is investigated by means of the initial-state radiation technique, where a photon emitted from incoming electron or positron. Using $454.3 \rm{fb}^{-1}$ data collected around center-of-mass energy $\sqrt{s} = 10.58 \rm{GeV}$ BaBar experiment at SLAC, approximately 150000 signal events are obtained. corresponding non-radiative cross section measured with relative uncertainty $3.6\%$ in region $1.5 \rm{GeV}$, surpassing all existing measurements...
The decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}_{S}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ has been studied using $430\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ events produced at a center-of-mass energy around 10.6 GeV the PEP-II collider and with BABAR detector. mass spectrum of ${K}^{\ensuremath{-}}{K}_{S}$ system measured...
A study of the two-body decays B^{±}→X_{cc[over ¯]}K^{±}, where X_{cc[over ¯]} refers to one charmonium state, is reported by BABAR Collaboration using a data sample 424 fb^{-1}. The absolute determination branching fractions for these are significantly improved compared previous measurements. Evidence found decay B^{+}→X(3872)K^{+} at 3σ level. fraction B[B^{+}→X(3872)K^{+}]=[2.1±0.6(stat)±0.3(syst)]×10^{-4} measured first time. It follows that B[X(3872)→J/ψπ^{+}π^{-}]=(4.1±1.3)%,...
We present measurements of Collins asymmetries in the inclusive process $e^+e^- \rightarrow h_1 h_2 X$, $h_1h_2=KK,\, K\pi,\, \pi\pi$, at center-of-mass energy 10.6 GeV, using a data sample 468 fb$^{-1}$ collected by BaBar experiment PEP-II $B$ factory SLAC National Accelerator Center. Considering hadrons opposite thrust hemispheres hadronic events, we observe clear azimuthal ratio unlike- to like-sign, and all charged $h_1 h_2$ pairs, which increase with hadron energies. The $K\pi$ are...
We study the processes e+e−→π+π−π0π0π0γ and π+π−π0π0ηγ in which an energetic photon is radiated from initial state. The data are collected with BABAR detector at SLAC. About 14 000 4700 events, respectively, selected a sample corresponding to integrated luminosity of 469 fb−1. invariant mass hadronic final state defines effective e+e− center-of-mass energy. From spectra, first precise measurement e+e−→π+π−π0π0π0 cross section ever e+e−→π+π−π0π0η performed. energies range threshold 4.35 GeV....
We study the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}{\ensuremath{\eta}}^{\ensuremath{'}}$ in double-tag mode and measure for first time ${\ensuremath{\gamma}}^{\ensuremath{\star}}{\ensuremath{\gamma}}^{\ensuremath{\star}}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}$ transition form factor ${F}_{{\ensuremath{\eta}}^{\ensuremath{'}}}({Q}_{1}^{2},{Q}_{2}^{2})$ momentum-transfer range $2<{Q}_{1}^{2}$, ${Q}_{2}^{2}<60\text{ }\text{...
We study the processes $e^+ e^-\to K^0_S K^0_L\pi^0\gamma$, $K^0_S K^0_L\eta\gamma$, and K^0_L\pi^0\pi^0\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic final states over a continuum of center-of-mass energies. The results are based on 469~$fb^{-1}$ data collected at or near $\Upsilon(4S)$~ resonance with BaBar detector SLAC. present first K^0_L\pi^0$, K^0_L\eta$, K^0_L\pi^0\pi^0$ sections up to energy 4~GeV, their intermediate...
Many scenarios of physics beyond the Standard Model predict existence new gauge singlets, which might be substantially lighter than weak scale. The experimental constraints on additional scalars with masses in MeV to GeV range could significantly weakened if they interact predominantly leptons rather quarks. At an $e^+e^-$ collider, such a leptophilic scalar ($\phi_L$) would produced through radiation from $\tau$ lepton. We report herein search for $e^+e^- \to \tau^+\tau^- \phi_L$, $\phi_L...